The present relates to apparatus for and a method of packaging semiconductors devices, and, more particularly, to a packaging apparatus and methods for plural devices which are manufactured and then placed in a package in a first orientation, but which customers to whom the packages are furnished desire to remove from the package in a different orientation.
One type of prior art semiconductor device is a ball grid array (xe2x80x9cBGAxe2x80x9d) device 10, generally depicted in FIG. 1. A BGA device 10 typically includes a substrate 12 carrying electrical conductive paths 14 and 16 on opposed surfaces 18 and 20 thereof, and electrical paths 22 formed within through-holes 24 through the substrate 12. The surface 18 of the substrate 12 also carries a semiconductor chip 30 that includes thereon and therein a variety of transistors and other devices.
The transistors and other devices of the chip 30 are rendered electrically continuous with selected ones of the paths 14 by wires 32 which are bonded to external transistor-connected pads on the chip 30 and selected paths 14. Selected paths 14 are connected to selected paths 16 via the through-hole paths 22. Eutectic solder balls 34 on the paths 16 permit the ultimate connection of the chip 30 to terminals or pads of utilization circuitry. The chip 30, the wires 32 and other portions of the device 10 may be covered with or encapsulated in insulative material 36 of selected formulations.
During and after the production of the BGA device 10, it is subjected to various visual, electrical and other inspections and tests. Ultimately, the completed device 10 is delivered to a packaging station, generally depicted by the reference numeral 38 in FIGS. 1 and 2, where the device 10 is packaged for delivery to and use by a customer.
The bonding of the wires 32, the encapsulation with the insulative material 36 and other operations utilized to produce the device 10 are typically carried out so that when the completed device 10 arrives at the packaging station 38, a first or upper surface 40 of the device 10 is oriented upwardly, while a second or lower surface 42 of the device 10 is oriented downwardly. This positioning of the device 10 orients the balls 34 downwardly.
Typically, and referring now to FIG. 2, large numbers of devices 10 are continuously delivered to the packaging station 38 oriented with their balls 34 down. Selected quantities of the devices 10 are then conveniently placed into multiple pockets 48, one device 10 per pocket 48, formed in a tray 50, sometimes referred to as a waffle pack, with their balls 34 down. A cover 52 may then be placed over and removably secured to the waffle pack 50 to retain the devices 10 therein. The waffle pack 50 and the contained devices 10 are then shipped to a customer.
Customers object to receiving the devices 10 in the waffle packs 50 ball-side-down. One reason for this objection is that customers"" utilization of the devicesxe2x80x94typically removal from the waffle pack 50 and placement in and connection to other circuitryxe2x80x94requires that the devices 10 be ball-side-up. Absent intervention by the device manufacturer, a customer must invert each device 10 into a ball-side-up orientation after its removal from the waffle pack 50.
Prior manufacturer intervention in this area has taken the following form: After a quantity of devices 10 have been loaded into an uncovered waffle pack 50, a second inverted waffle pack 52 is placed and held thereover so that the pockets 48 in each waffle pack 50,52 are aligned. At this point, the waffle pack 50 is below the superjacent waffle pack 52. The waffle pack 50,52 xe2x80x9csandwichxe2x80x9d is then inverted reversing the upper and lower positions of the waffle packs 50,52 so that the waffle pack 50 originally holding the devices is now upside-down. This inversion allows the devices 10 to fall from the pockets 48 of the waffle pack 50 ball-side-up into the pockets 48 of the now lowermost, right-side-up waffle pack 52. The waffle pack 52 is then covered and shipped to a customer, who is able, as desired, to remove the devices 10 therefrom ball-side-up.
Typically, waffle packs 50,52 for BGA devices 10 contain numerous pockets. Aligning these pockets in the waffle packs 50,52 can be difficult and time-consuming. It is likely that some of the devices 10 will not drop into the pockets 48 of the waffle pack 52 upon inversion of the packs 50,52 because of misalignment of the pockets 48,48 or because of a device 10 xe2x80x9ccockingxe2x80x9d in the pockets 48 of one or the other pack 50,52. It has also been found that the application of force to the packs 50,52 during the inversionxe2x80x94such as may occur when the packs 50,52 are tapped to encourage the devices 10 to fall or due to the impact of the devices 10 against the pockets 48 in the pack 52 incident to fallingxe2x80x94may damage the devices 10.
One aim of the present invention is the provision of a method and apparatus which simplify orienting devices 10 according to customers"" wishes, which method and apparatus obviate the shortcomings of the prior method.
The premise for the method and apparatus of the present invention is that articles, which may be BGA semiconductor devices or the like, are presented at a work station, such as a packaging station, in a certain orientation that is caused by or results from prior operations such as manufacturing or testing. In the case where the article is a BGA device, the orientation at the work station results in ball contacts thereon being downward, that is, the devices are presented to the station ball-side-down. It is desired to present multiple articles to customers in a pocketed container in a different or inverted orientation, in the case of the BGA devices ball-side-up. Further, it is desired to achieve inversion of the articles without dropping the articles from a first container into a second aligned container by inverting the two containers so the articles drop from the first to the second container in an inverted orientation.
Instead of using a pocketed container at the work station, a member or transfer body is secured which has apertures formed therethrough, that is, all the way through the member as open apertures. The apertures are conformal with the periphery of the articles so that once an article is therein, it cannot rotate and is securely held therein. One end of the apertures is closed to render them blind apertures. Conveniently this may be achieved by fixing a first removable cover to the side of the member at which the ends of the apertures are located.
Next, the articles are inserted into the apertures at the work station, using, in effect, the first removable cover as a xe2x80x9cbottomxe2x80x9d against which the articles abut. In the case of BGA devices, the balls thereof abut and are supported by the first cover and the opposed surface of the BGA devices are exposed at the work station. Now the other ends of the blind apertures are closed, conveniently by a second removable cover. This renders the apertures closed apertures. Thereafter, the member is inverted. This inverts the articles converting the first cover into a xe2x80x9ctopxe2x80x9d cover and the second cover a xe2x80x9cbasexe2x80x9d which supports the devices in their inverted orientation. This inverted orientation in the case of BGA devices is ball-side-up. Removal of the first cover, now the xe2x80x9ctopxe2x80x9d cover, exposes the inverted articles, specifically the BGA device balls, the orientation preferred by customers.